JP5554422B2 - Digital communication system with variable bandwidth traffic channel - Google Patents

Description

  The present invention relates to a digital communication system having a variable bandwidth traffic channel.

  This application is a priority of US Provisional Patent Application No. 61 / 302,505 filed on Feb. 8, 2010, and US Patent Application No. 12 / 887,468 filed on Sep. 21, 2010. These patent applications are hereby incorporated by reference.

  Electronic devices such as computers, media players and cellular telephones typically include an audio jack. Accessories such as headsets have mating plugs. A user who wants to use a headset with an electronic device connects the headset to the electronic device by inserting a headset plug into the mating audio jack of the electronic device. Electronic devices such as notebook computers and media players typically use small size (3.5 mm) telephone jacks and plugs. This is because such an audio connector is relatively compact.

  Audio connectors commonly used to handle stereo audio have a tip connector, a ring connector and a sleeve connector, sometimes referred to as a three-contact connector or a TRS connector. Devices such as cellular phones often need to transmit microphone signals from the headset to the cellular phone. In configurations where it is desired to handle both stereo audio signals and microphone signals, audio connectors typically include additional ring terminals. Such an audio connector has a tip, two rings and a sleeve and is therefore sometimes referred to as a four-contact connector or a TRRS connector.

  Audio signals are typically carried in analog form between the electronic device and the accessory. For example, left and right audio tracks are typically carried to a stereo handset as analog signals using the “left” and “right” channel wires of the headset cable.

  Improving audio fidelity and supporting additional audio channels with this type of analog signaling scheme is difficult or impossible without providing additional analog signal wires in the headset cable. This type of configuration is not compatible with existing audio connectors.

  It would therefore be desirable to be able to provide an improved technique for transmitting signals such as audio signals between electronic devices and external devices.

  Electronic devices and devices communicate via a wired communication path. A wired communication path includes one or more wires and is associated with a cable, such as a cable for a pair of headphones or other accessories. Electronic devices and devices include components that generate and consume audio data, such as microphones and speakers.

  Audio data and other data is carried over the wire of the cable using a differential transmitter and receiver circuit. Data is carried in the form of a digital data stream that includes multiple traffic channels. The digital data stream includes superframes each having a plurality of data frames. Each data frame includes a number of data slots. Some of the slots in the superframe are used exclusively by a particular one of the traffic channels. Boundary slots are shared between traffic channels. The data interface circuit implements a data distribution algorithm that determines the pattern in which data from each traffic channel is distributed within each boundary slot. The transmit data interface circuit merges the traffic channel into a single data stream at one end of the wired communication path. The receive data interface circuit reconfigures the traffic channel at the other end of the wired path. That reconfigured traffic channel is then distributed to each speaker or other component.

  Further features of the invention, its nature and various advantages will be apparent from the accompanying drawings and the following detailed description of the preferred embodiments.

1 is a schematic diagram of an exemplary electronic device in communication with an accessory, such as a system handset or other external device, according to one embodiment of the invention. FIG. FIG. 2 is a diagram of an exemplary audio connector and associated switching circuit used in an electronic device and external device to form a wired communication path between the electronic device and the external device according to an embodiment of the present invention. FIG. 3 is a circuit diagram illustrating how differential signaling is used to carry digital data over a communication path of the type shown in FIG. 2 according to an embodiment of the present invention. 3 is a circuit diagram of an exemplary electronic device circuit that generates and consumes data carried over a wired communication path of the type shown in FIG. 2 according to one embodiment of the present invention. 3 is a circuit diagram of an exemplary speaker-based endpoint communicating with a host electronic device via a wired communication path of the type shown in FIG. 2 according to one embodiment of the present invention. 3 is a circuit diagram of an exemplary microphone-based endpoint that communicates with a host electronic device via a wired communication path of the type shown in FIG. 2 according to one embodiment of the invention. FIG. 3 is a circuit diagram illustrating an exemplary data allocation circuit serving as an interface between a plurality of traffic channels and a stream of digital data carried over a wired communication path of the type shown in FIG. 2 according to one embodiment of the present invention. FIG. 3 is a diagram of an exemplary data structure used to carry data over a wired communication path of the type shown in FIG. 2 according to one embodiment of the present invention. 4 is a table showing how data bytes of different traffic channels are allocated between slots of a frame in a superframe according to an embodiment of the present invention. 4 is a flowchart of exemplary steps involved in determining how to allocate data bytes in a data stream according to an embodiment of the present invention. 4 is a flowchart of exemplary steps involved in carrying digital data over a communication path between an electronic device and an external device according to an embodiment of the invention.

  Electronic components such as electronic devices and other devices are interconnected using wired and wireless paths. For example, a wireless path is used to connect a cellular phone to a wireless base station. Wired and wireless paths are also used to connect electronic devices to devices such as computer peripherals and audio accessories. As an example, a user uses a wired or wireless path to connect a portable music player to a headset.

  Electronic devices that are connected to external devices using wired or wireless paths include desktop computers and portable electronic devices. Portable electronic devices include laptop computers and small portable computers of the type sometimes referred to as ultraportable. Portable electronic devices also include slightly smaller portable electronic devices such as wristwatch devices, pendant devices, and other wearable small devices.

  Electronic devices connected to external devices include cellular phones, media players with wireless communication capabilities, handheld computers (also called personal digital assistants), remote controllers, global positioning system (GPS) devices, and handheld game devices. It is also a handheld electronic device. The hybrid electronic device can receive, for example, a cellular phone including a media player function, a gaming device including a wireless communication function, a cellular phone including a game and an e-mail function, and an e-mail to support a mobile phone call, a music player Includes portable devices that have functionality and support web browsers. These are merely examples.

  An external device connected to such an electronic device is, for example, an accessory such as a headset. A headset typically includes a pair of speakers that can be used by a user to play audio from an electronic device. The headset or other accessory also includes one or more microphones and a user interface such as one or more buttons and a display. When the user provides input to the user control interface, the input is conveyed to the electronic device.

  The external device connected to the device also includes a device such as an adapter. The adapter is, for example, a tape adapter that has an audio plug at one end and a cassette at the other end and is slid to a tape deck such as an automobile tape deck. Devices such as tape adapters are used to play music or other audio via speakers associated with the tape deck. An audio device such as a user home or car stereo system is also connected to the electronic device. For example, a user connects a music player to a car sound system.

  Accessories such as headsets are typically connected to electronic devices using an audio plug (male audio connector) and a mating audio jack (female audio connector). Such audio connectors are provided in various form factors. Most commonly, audio connectors take the form of 3.5 mm (1/8 ") mini plugs and jacks. Other sizes such as 2.5 mm sub mini connectors and 1/4 inch connectors are sometimes used. For accessories such as headsets, these audio connectors and associated cables are typically used to carry analog signals such as speaker audio signals and microphone signals Universal Serial Bus (USB) ) And Firewire (R) (IEEE 1394) connectors are also used by electronic devices to connect to external devices such as headsets, but generally like 3.5mm audio connectors Headset using standard audio connector It is preferable to connect to an electronic device, such as a USB connector and an IEEE 1394 connector, mainly when a large amount of digital data needs to be transferred to an external device, such as when connecting to a peripheral device such as a printer. Especially in environments that carry high bandwidth traffic such as video traffic, optical connectors that are integrated with digital and analog connectors are used to transfer data between electronic devices and related accessories. If desired, the audio connector can include an optical communication structure to support this type of traffic.

  Audio connectors used to connect electronic devices to external devices have a number of contacts. Stereo audio connectors typically have three contacts. The outermost end of the audio plug is typically referred to as the tip. The innermost part of the plug is typically referred to as a sleeve. A ring contact exists between the tip and the sleeve. When using this terminology, such a stereo audio connector is sometimes referred to as a tip-ring-sleeve (TRS) connector. The sleeve acts as a grounding part. The tip contact is used in connection with the sleeve to handle the left audio channel, and the ring contact is used in connection with the sleeve to handle the right audio channel (as an example). In a four-contact audio connector, additional ring contacts are provided to form a type of connector sometimes referred to as a tip-ring-ring-sleeve (TRRS) connector. The 4-contact audio connector is used to handle microphone signals, left and right audio channels, and ground (as an example).

  In addition, the electric device and the external device can operate in various modes. For example, a cellular phone is used in a music player mode to play stereo audio to the user. The same cellular telephone, when operated in telephone mode, is used to process the telephone call microphone signal from the user while simultaneously playing back the left and right audio signals of the telephone call to the user. When playing back audio that includes more than two information channels (eg 5.1 surround sound), more than five audio data channels are played back simultaneously. The noise cancellation function includes transmitting one or more audio streams associated with the microphone.

  In a typical scenario, an electronic device connected to an external device via a wired path generates an audio signal. These audio signals are transmitted to an external device in the form of analog audio (as an example). The external device includes a microphone. A microphone signal (eg, an analog audio signal corresponding to the user's voice or other sound) is conveyed to the electronic device using a wired path. Wired paths are also used to carry other signals such as power signals and control signals.

  In some situations, it is difficult or impossible to carry the signal in analog form. For example, support multi-channel audio (eg 5.1 surround sound audio) when devices and handsets are combined using a 4-contact audio connector (eg 3.5 mm TRRS jack and plug) and associated 4-wire cable There may not be a sufficient number of analog signal paths. Analog formats are more susceptible to noise than digital signals.

  These shortcomings of analog formats are addressed by providing digital communication capabilities in electronic devices and external devices. By transmitting data efficiently, power consumption can be minimized and battery life can be extended. An efficient digital communication scheme can be implemented that avoids encoding data with an excessive number of data bits per channel and avoids encoding data using an excessive bit rate. Since latency has an adverse effect on audio performance, in such an efficient digital communication scheme, care can be taken to transmit data in a manner that minimizes latency.

  An exemplary system in which an electronic device uses such a digital communication scheme is shown in FIG. As shown in FIG. 1, the system 10 includes an electronic device such as an electronic device 12 and an external device 14. The electronic device 12 is sometimes referred to as a host. The external device 14 is sometimes referred to as an electronic accessory or device.

  The electronic device 12 is a desktop or portable computer, a portable electronic device such as a handheld electronic device with wireless capabilities, a device such as a television or audio receiver, or other suitable electronic device. The electronic device 12 may be provided in the form of a stand-alone device (eg, a handheld device carried in a user's pocket) or as an embedded system. The systems in which the device 12 is embedded include, for example, automobiles, boats, aircraft, homes, security systems, commercial and home media distribution systems, display devices (eg, computer monitors and televisions), and the like.

  External device 14 may be a car with a sound system, a consumer electronic device such as a television or an audio receiver with audio capability, a peer device (eg, another electronic device such as device 12), a headset, etc. A device such as an accessory or other suitable electronic device. The device 14 includes one or more endpoints 22. Each endpoint is associated with an electronic component that generates or consumes data, such as a speaker or a microphone.

  Device 12 includes a data interface circuit 18. Device 14 includes a data interface circuit 20. These data interface circuits 18 and 20 are used as transmitters and receivers. During digital communication, the data interface 18 packages the digital data generated by the device 12 and transmits the data to the device 14 via the path 16. The data interface 20 receives the data transmitted from the path 16 and distributes the digital data to the endpoints 22 via each traffic channel TC1,... TCN. The process of transferring data from device 12 to device 14 is sometimes referred to as the downlink process, and data interface 18 is sometimes referred to as the downlink interface.

  Digital data is also transmitted from the endpoint 22 to the device 12. This process is sometimes referred to as the uplink process, and the data interface 20 is sometimes referred to as the uplink interface in this capacity. During uplink operation, the data traffic of each traffic channel TC1,... TCN is combined by the uplink interface into a data stream for transmission over path 16.

  One example of a downlink process is distributing audio data to speakers. The device 14 includes, for example, five speakers (driver, driver set, etc.). The distributed audio data corresponds to, for example, five channels of audio data. Data interface 20 receives a stream of data from data interface 18 via path 16. The stream of data includes data bytes corresponding to each of the five audio data channels. The data interface 20 separates the audio data stream into five traffic channels, each carrying audio data for each of the five audio channels. Each of the five endpoints receives digital data and plays back five audio channels using internal digital / analog converter circuitry, amplifier circuitry and drivers.

  One example of an uplink process is distributing microphone audio from one or more microphone-based endpoints 22 of device 14. The microphone is used to collect noise cancellation data or voice data for telephone calls. The endpoint is provided with an analog / digital converter circuit for digitizing the microphone signal. Microphone signals from one or more endpoints are sent to the data interface 20 via one or more corresponding traffic channels TC1,... TCN. The data interface 20 multiplexes audio data from each microphone on the path 16 as a stream of digital data.

  Path 16 includes a cable having conductive lines. In general, path 16 has a suitable number of lines. For example, there are 2, 3, 4, 5, or 6 or more individual lines. These lines are part of one or more cables. Cables include solid wire, braided wire, shielded wire, single grounded structural wire, multiple grounded structural wire, twisted pair structural wire, or other suitable cable structural wire.

  To ensure compatibility with legacy devices such as conventional headsets, it is advantageous to use a standard audio connector, such as a 3.5 mm audio connector, at one or both ends of the conductive line in path 16. These connectors are widely used for handling audio signals. Audio connectors, such as 3.5 mm audio connectors, are also relatively compact and can minimize the size of device 12 and device 14. The conductive line of the path 16 is accommodated in the cable. Audio connectors are provided at one or both ends of the cable. For cables that have an audio connector only at one end, the other cable end is used to form a fixed wiring connection. In a typical configuration, one end of the cable is fixedly wired to the circuit of the device 14 and a male audio connector (ie, TRRS plug) is provided at the other end of the cable. The device 12 is provided with a mating female audio connector (ie, a TRRS jack).

  An exemplary configuration of this type is shown in FIG. As shown in FIG. 2, the path 16 includes a conductive line 88 of the cable 70. One end of the cable 70 is terminated to the device 14. An audio plug 34 is provided at the other end of the cable 70. The audio plug 34 is fitted into the audio jack 38 of the device 12.

  As shown in FIG. 2, the electronic device 12 is provided with a switching circuit 160 and the device 14 is provided with a switching circuit 164. In the analog signaling mode, the switching circuit 160 is configured such that the analog signal line 170 is coupled to the contact of the jack 38 and the switching circuit 164 is configured such that the analog signal line 174 is coupled to the contact of the plug 34. Is done. In the digital signaling mode, switching circuit 160 is configured such that digital signal line 172 is coupled to the contact of jack 38 and switching circuit 164 is configured such that digital signal line 176 is coupled to the contact of plug 34. Is done. Mixed modes where a combination of digital and analog signals exist are also supported. Analog lines 170 and 174 are used to carry power supply signals if desired.

  The audio plug 34 is an example of a four-contact plug. The four conductive areas of the four-contact plug fit into four corresponding conductive areas of a four-contact jack, such as jack 38. As shown in FIG. 2, these regions include a tip region such as region 48, a ring region such as rings 50 and 52, and a sleeve region such as region 54. These regions surround the cylindrical surface of the plug 34 and are separated by an insulating region 56. When the plug 34 is inserted into the mating jack 38, the tip region 48 is in electrical contact with the jack tip contact 74, the rings 50 and 52 fit into the respective ring regions 76 and 78, and the sleeve 54 is a sleeve terminal. 80 is contacted. In a typical configuration, cable 70 has four wires, each of which is electrically connected to a respective contact.

  The signal designation used for the audio connector 46 depends on the type of electronic device and accessory used. In one typical configuration, ring 52 serves as a ground. During analog signal communication, tip 48 and ring 52 are used together to handle the left analog audio channel (eg, the signal of the left speaker of the headset), and ring 50 and ring 52 are the right channel analog audio. Used against. In a device that includes a microphone, the ring 52 and sleeve 54 are used to carry the analog microphone audio signal from the device to the electronic device 12 during the analog signaling mode. Other signal designations are also used if desired.

  During digital communication, the wires of cable 70 and the corresponding contacts of connectors 38 and 34 are used to carry digital signals. For example, a pair of conductors of cable 70 and a corresponding pair of contacts of connectors 38 and 34 are used to implement a differential signaling scheme of the type shown in FIG.

  The electrical connection between the mating contact pairs at the jack 38 and the plug 34 is made at terminals C1 and C2. The device 12 includes a differential transmitter TA and a differential receiver RA. The device 14 includes a differential transmitter TB and a differential receiver RB. During downlink operation, device 12 receives single-ended data at input INA and uses transmitter TA to transmit this data in differential form to conductive lines W1 and W2 (ie, cable 70 of FIG. 2). To transmit via a twisted pair of wires 88). The receiver RB receives the transmitted differential signal and converts the received differential signal into single-ended digital data at the output OUTB. During uplink operation, single-ended data at the input INB of the transmitter TB of the device 14 is transmitted in differential form to the receiver RA of the device 12 using the transmitter TB. The receiver RA converts the received differential data into single-ended data at the output OUTA. The wires W1 and W2 are selected from two of the wires in the cable 70 (for example, left and right audio lines, microphone and ground line, etc.). The remaining lines are used for additional data signals, analog signals, power signals, etc.

  Signals carried via path 16 include control signals, audio signals, video signals, or other suitable signals. The transmission and reception of audio signals is described herein as an example.

  FIG. 4 shows an exemplary audio circuit used to process the audio signal of system 10. The audio circuit 180 is disposed in the device 12 or the apparatus 14. For example, the audio circuit 180 is disposed in the device 12 and is used to generate an analog audio signal and a digital audio signal. Audio codec 182 is implemented using one or more integrated circuits. This codec 182 and other circuitry within the audio circuit 180 includes an analog / digital converter 184 and a digital / analog converter 186. The analog / digital converter 184 is used to convert a received analog signal (eg, an analog microphone signal from the microphone of the device 12 or device 14) into digital audio data. The digital / analog converter 186 is used to convert digital audio data into analog audio data (eg, analog speaker signal). Digital signal processor 188 is used to process the digital audio signal. For example, digital signal processor 188 receives a digital microphone signal via path 16 or from analog to digital converter 184, and also receives digital audio data corresponding to playback media from audio circuit 180 of device 12 or device 14. And processing the digital information to generate a noise-canceled audio signal. Input / output line 190 is used to transmit and receive analog and digital signals. For example, multiple lines 190 can be used to transmit or receive digital data associated with each traffic channel.

  In a typical configuration, audio circuit 180 is located in device 12 and receives digital audio data from one or more endpoints while transmitting digital audio signals to one or more endpoints of apparatus 14. Input / output line 190 is used to transmit and receive data. The endpoints of the device 14 include one or more endpoints that generate data for transmission to the device 12 via the path 16 and one or more endpoints that consume data received via the path 16 from the device 12. including.

  An example of an endpoint that consumes data is a speaker-based endpoint of the type shown in FIG. As shown in FIG. 5, endpoint 200 includes an input, such as input 198, that receives digital data (eg, traffic channel data) carried via path 16. The digital / analog converter 192 converts the digital signal at the input 198 into an analog signal at the output 199 corresponding thereto. Amplifier 194 amplifies the analog signals on path 199 and sends the amplified form of the analog signals to speaker 196 to generate sound.

  An example of an endpoint that generates data is a microphone-based endpoint of the type shown in FIG. As shown in FIG. 6, the endpoint 202 includes a microphone, such as a microphone 204. The microphone 204 converts sound into an analog signal. The analog / digital converter 206 converts the analog microphone signal from the microphone 204 into a digital output signal (eg, traffic channel data) on the path 208.

  FIG. 7 is a circuit diagram illustrating exemplary circuitry used to implement a data interface, such as data interface 18 and data interface 20 of FIG. Each data interface typically has multiple input / output paths, such as path 212, coupled to each endpoint. Path 212 carries each data traffic channel (eg, traffic channel TC1,... TCN in FIG. 1). Buffer 214 (eg, first in first out buffer) is used to buffer input and output data and serves as each interface between data allocation circuit 216 and circuitry coupled to path 212. The channel assignment setting 218 is stored in a memory of the data assignment circuit 216 (for example, a register of the circuit 216). Settings 218 include information used by data allocation circuit 216 to multiplex and demultiplex data.

  During a typical multiplexing operation, the data input / output path 212 receives data (eg, from an endpoint microphone, from the path 190 of the audio circuit 180 of FIG. 4, or from other suitable sources). This data is temporarily stored in the buffer circuit 214. Each buffer handles data for each data channel. Data allocation circuit 216 uses channel allocation information 218 to allocate data from each buffer to the appropriate location in the outgoing data stream. This outgoing data stream is transmitted via first in first out buffer 220 and path 222. Path 222 is coupled to, for example, input INA or input INB of FIG.

  During a typical demultiplexing operation, path 222 receives data from OUTA or OUTB of FIG. 3 and buffers this data in buffer 220. The data allocation circuit 216 uses the channel allocation settings 218 to determine how to demultiplex the data in the incoming data stream and thus how to reconfigure the traffic channel. The demultiplexed data is routed to path 212 via an appropriate buffer 214.

  Data allocation circuit 216 controls the flow of data through these buffers by generating a clock for each of buffers 214 and 220. For example, if a particular data item received in buffer 220 is to be assigned to a particular traffic channel, data assignment circuit 216 may send a clock pulse to the buffer associated with that traffic channel (eg, one of buffers 214). Simultaneously, the clock for buffer 220 is incremented. This moves the data from buffer 220 to the appropriate one of buffers 214. The same type of buffer clock control scheme can be used when the data allocation circuit 216 operates in reverse (ie, when data from each traffic channel is allocated to the composite data stream on path 222).

  Bidirectional data transmission can be supported on path 16 by using a data interface circuit, such as the circuit of FIG. In order to avoid contention, the data interface circuit alternates sending and receiving data (ie, time division techniques are used where path 16 acts as either an uplink path or a downlink path at a given time. ) Simultaneous uplink and downlink operations are also supported (eg, by providing additional physical paths or using circuitry that supports simultaneous bidirectional signaling).

  Digital data transmitted and received by the data interfaces 18 and 20 are packaged using a suitable data structure configuration. In one suitable configuration shown in FIG. 8, data (eg, data stream DS) is carried using a series of superframes. Each super frame includes a plurality of frames. Each frame then includes a plurality of data slots. Each data slot may be left empty or filled with bytes of data. The data bytes in each slot may be unencoded (eg, by using 8-bit or 16-bit words) or encoded (eg, as 10-bit 8B / 10B encoded data bytes). .

  In the example of FIG. 8, there are three layers (superframe, frame and slot) of the data structure. If desired, fewer nested layers of data structures or more nested layers of data structures may be used for data stream DS. The example of FIG. 8 is merely illustrative.

  In one exemplary configuration, 160 frames are nested within each superframe, and there are 34 data slots per frame. Each data slot filled with data includes one 8-bit byte encoded using 8B / 10B encoding (ie, to form a 10-bit encoded form of 8-bit bytes). Other types of encodings and different numbers of frames and data slots may be used as needed. Each superframe has a duration of 3 1/3 milliseconds (as an example). The data rate of the data stream DS is about 9 MHz, for example. This data rate is low enough to allow twisted pair wires such as wires W1 and W2 in FIG. 3 to be treated as DC (direct current) wires. At typical path lengths (eg, less than 1 meter), the time delay experienced by signals traveling along the wires W1 and W2 of path 16 is significantly less than the bit width. Using this type of signaling scheme, the amount of power consumed when carrying a signal over path 16 is rather modest (eg, less than 1 mW), and this type of scheme can be used for small battery powered devices. Suitable for use in

  Audio data must be transported with low latency to avoid generating unwanted audio artifacts. Even when the steady amount of data in each traffic channel does not uniformly match an integer number of slots per frame, latency and power consumption can be minimized by evenly distributing the data across the data slots.

  The amount of data to be carried over each traffic channel will vary based on factors such as user-defined and default settings, link quality, media type, encoding scheme, etc. For example, a voice telephone call without noise cancellation may have less bandwidth than a high quality 5.1 channel surround sound signal. Therefore, the amount of bandwidth associated with the data stream DS varies based on the needs of the system 10. In situations where only a relatively small bandwidth is required, less data is carried per unit time. When relatively little data is carried, many, if not most, of the data slots in each frame are not occupied, thus reducing power consumption in the transmit and receive circuits. When a large amount of bandwidth is required, a corresponding number of data slots are occupied with data. In this type of state, power consumption is slightly higher.

  In certain situations, the amount of bandwidth required by a given traffic channel on path 16 may require the use of a small number of data slots (eg, 3.375) per frame. This number of data slots required per frame is satisfied by provisioning path 16 to designate a sufficiently large integer number of slots per frame (eg, 4 slots / frame) for a given traffic channel. be able to. Although possible, this type of provisioning scheme tends to over-allocate bandwidth to a given traffic channel and increase power consumption.

  The number of slots allocated to each traffic channel is allowed to vary from frame to frame in order to minimize power consumption while minimizing latency and assuring high quality audio playback. In this type of scheme, the average number of slots per frame need not be an integer. As slot designations continue to change, both the transmitter and receiver can be given enough information to identify the slot fill pattern currently in use. At the data interface associated with the transmit side of path 16, for example, a data allocation circuit, such as data allocation circuit 216 in FIG. 7, uses channel allocation settings 218 to route data from each traffic channel to a slot in data stream DS. And how it is distributed over the frame. At the data interface associated with the corresponding receiver on path 16, a data allocation circuit, such as data allocation circuit 216, uses the same channel allocation settings to extract data from the data stream DS to traffic channel. Can be reconfigured.

  For example, consider the configuration shown in FIG. In the example of FIG. 9, there are four different traffic channels: channel a, channel b, channel c, and channel d. Channel a has a bandwidth requirement of 54 slots per superframe, channel b has a bandwidth requirement of 70 slots per superframe, and channel c has a bandwidth requirement of 23 slots per superframe. And channel d has a bandwidth requirement of 38 slots per superframe. The table of FIG. 9 shows a pattern in which the data bytes for each traffic channel are distributed over a single superframe slot and frame. The superframe of FIG. 9 has 16 frames (0... 15), and each frame has 13 slots. The number of frames and slots in the superframe of FIG. 9 has been selected to help simplify the drawing. Other numbers of frames and slots may be used as needed.

  As shown in FIG. 9, data traffic is distributed differently from frame to frame. In frame 0, slots 1-4 are filled with each data byte of traffic channel a, slots 5-8 are filled with each data byte of traffic channel b, and slots 9 and 10 are filled with traffic channel c. Are filled with each data byte, slots 11 and 12 are filled with each data byte of traffic channel d, and slot 13 is empty. In frame 1, slots 1-3 are filled with data bytes of traffic channel a, slots 4-8 are filled with data bytes of traffic channel b, and slot 9 is filled with data bytes of traffic channel c. Data bytes are filled, slots 10-12 are filled with each data byte of traffic channel d, and slot 13 is empty. Also, subsequent frame slots are filled differently.

  As shown in FIG. 9, the point at which data transitions between adjacent channels is not uniform (that is, the slot position where the data of channel a transitions to the data of channel b varies from frame to frame). In frame 0, the transition between channel a and channel b occurs between slots 4 and 5, and in frame 1, the transition between channel a and channel b is between slots 3 and 4. Arises, and so on.

  An orderly process that can extract data from multiple traffic channels into a single data stream at one end of path 16 and reconstruct each of the multiple traffic channels at the other end of path 16 comprises: It can be implemented using a data distribution algorithm. In one suitable configuration, data interfaces 18 and 20 each have a data allocation circuit (such as circuit 216 in FIG. 7) that implements a data distribution algorithm of the type shown in FIG. The algorithm of FIG. 10 is used, for example, to form the data distribution of FIG. The data distribution algorithm determines the pattern in which data from each traffic channel is assigned to each frame slot. For example, the data distribution algorithm allows both the transmitter and receiver to determine the slot position of the transition between channels for each frame. The algorithm of FIG. 10 is merely illustrative. Other data distribution algorithms may be used by the data interface circuits 18 and 20 as needed.

  In step 224, the root of the data distribution process (ROOT) is selected. The parameter ROOT serves as a seed for the data distribution algorithm. The route is, for example, an appropriate prime number. After selecting the value of ROOT, the index i is initialized (for example, to 0).

  According to the first embodiment of the data distribution algorithm of FIG. 10, the process then proceeds to step 226. According to the second embodiment of the data distribution algorithm of FIG. 10, the process then proceeds to step 228.

  In the solution of step 226, the frame number parameter Ri is calculated by calculating the product of index i and ROOT modulo NF. However, NF is the number of frames present in each superframe (16 in the example of FIG. 9). In the solution of step 228, each Ri value is calculated using another set of equations shown in FIG.

After calculating the value of R _i for each i (ie, for all i values from 0 to NF-1 if NF is the number of frames per superframe), the process goes to step 230. move on. During the operation of step 230, the REMAINDER value for the traffic channel is calculated by calculating the cumulative number of slots per superframe for each traffic channel's modulo NF. For channel a in this example, SLOTS / SUPERFRAME is equal to 54 and NF is 16, so SLOTS / SUPERFRAME mod NF is 6. This value (i.e., 6 in this example) represents the number of extra bytes of data that are filled into the slot at the boundary between channels a and b. This type of slot is sometimes referred to as a boundary slot. In the calculation of REMAINDER for channel B, the accumulated value of SLOTS / SUPERFRAME is 124 (54 slots for traffic channel + 70 slots for traffic channel b). Therefore, the value of REMAINDER for traffic channel b is 12 because 124 mod 16 = 12. When the value of REMAINDER for traffic channel c (boundary slot 8) and traffic channel d (boundary slot 12) is detected, the accumulated value of SLOTS / SUPERFRAME is similarly calculated.

  As shown in FIG. 9, slots 1, 2 and 3 in each frame are filled with data for channel a and are therefore not boundary slots. Similarly, slots 4, 6 and 7 are completely filled with data from traffic channel b and are not boundary slots. However, slot 4 is partially populated with data traffic from channel a and partially populated with data traffic from channel b. Slot 4 is therefore a boundary slot (representing the boundary between channels a and b). Similarly, slot 8 is a boundary slot for channels b and c, and so on.

In step 232, for each traffic channel, comparing each R _i value to the value of the REMAINDER for that traffic channel. If the R _i value is lower than the REMAINDER value for that traffic channel, Bi for that traffic channel is set to 1 (ie, from the traffic channel to the boundary slot between that traffic channel and the next traffic channel). Should be filled with data). If R _i is greater than REMAINDER is, Bi is set set to 0 (i.e., the boundary slot between the traffic channel and the next traffic channel should not be filled with data from the traffic channel).

  The way this process works to distribute the data for channel a to slot 4 is by comparing the R value in the “R” column of the table of FIG. 9 with the calculated REMAINDER value for channel a (ie, 6). It will be clear. In frame 0, R = 0 and 0 is less than 6, so B0 is set to 1 and the data on channel a is used to fill slot 4 of frame 0. However, in frame 1, R = 7, and 7 is greater than 6, so B1 is set to 0 and the data in channel a is not used to fill slot 4 of frame 0 (rather, in frame 0 The data of channel b is used to fill slot 4). This scheme applies to all calculated R values (R0... R15) in “R” of FIG. 9 (ie, all frames of the superframe).

  The pattern of data bytes in each boundary slot (shown as channel assignment setting 218 in FIG. 7) is cached for later use or the data bytes in each boundary slot using the data distribution algorithm of FIG. The pattern is calculated in real time. The channel assignment information is stored in an appropriate format (eg, using the REMAINDER value information, using the Ri value information for all frames, using the Bi value for all frames, etc.).

  Illustrative steps involved in sending and receiving data over path 16 using data interface 18 and data interface 20 are shown in FIG.

  In step 234, the channel capacity of each data traffic channel is determined. For example, if device 12 wishes to carry a 5.1 channel surround sound signal while playing audio from a media file, the number of traffic channels and bandwidth required for each channel is Is confirmed by the memory and processing circuit. The capacity of each channel is quantified with respect to the number of bytes of data to be transferred per superframe (eg, 54 bytes / superframe for channel a in the example of FIG. 9).

  In step 236, the position of the boundary slot in each superframe is determined (eg, using a known number of bytes in each traffic channel to be transmitted per superframe). In the example of FIG. 9, the boundary slot of channel a is slot 4. During the operation of step 236, a data distribution algorithm such as the algorithm of FIG. 10 is used to determine the pattern in which the data for each traffic channel should be assigned to the slot of each frame. For example, the data distribution algorithm dictates how data from each traffic channel is allocated within a boundary slot, as described with reference to FIG. The result of the data distribution algorithm is stored in the data interface 18 and data interface 20 (eg, this information is cached in the data allocation circuit 216 as shown by the channel allocation setting 218 in FIG. 7). Device 12 and / or apparatus 14 are used to perform the operations of steps 234, 236 and 238.

  After the setup operations of steps 234, 236 and 238 have been performed, data traffic is carried using link 16 (step 240). During the operation of step 240, the data allocation circuit of data interface 18 and the data allocation circuit of data interface 20 perform real-time data distribution calculations to determine how data bytes should be placed in the slots of each frame. Alternatively, the cache value of the channel assignment setting 218 is used to determine how to assign data. The transmit data interface merges the plurality of traffic channels into the data stream DS at one end of the path 16, and the receive data interface reconstructs the traffic channel from the reception form of the data stream DS at the other end of the path 16. The end point 22 is provided with data of each traffic channel.

  This scheme is flexible enough to accept a wide range of data rates and traffic channel bandwidths. For example, in situations involving small traffic channels, the number of slots used by each traffic channel per superframe is small enough to allow three or more traffic channels to coexist in a single slot. An example of this type of configuration is that traffic channel a uses 18 slots per superframe, traffic channel b uses 5 slots per superframe, and traffic channel c uses 7 slots per superframe. And traffic channel d uses 22 slots per superframe. If there are 16 frames per superframe (in this example), slot 1 is completely filled with traffic from channel a and slot 3 is completely filled with traffic from channel d. Slot 4 is used to accommodate four extra data bytes from traffic channel d. Slot 2 (in this example) is a boundary slot that carries traffic from 4 channels (2 bytes from channel a, 5 bytes from channel b, 7 bytes from channel c, and 2 bytes from channel d) Work as. The data distribution algorithm of FIG. 10 is used to distribute data from each of these four channels in slot 2 to minimize latency. Since multiple channels can use the same slot, the number of slots used to carry data is minimized.

  According to one embodiment, in a method for carrying data over a communication path, a transmission data interface obtains data corresponding to a plurality of traffic channels, and a transmission data allocation circuit in the transmission data interface includes a plurality of data Combining data from each of the traffic channels into a single data stream, where the data stream includes a stream of superframes, each superframe includes a plurality of frames, and each frame includes a plurality of at least one boundary slot. And the boundary slot carries data for one traffic channel of the plurality of traffic channels in the first subset of frames in a given superframe, and the boundary slot further comprises: The method comprising conveying the data to another traffic channel of the plurality of traffic channels in a second subset of frames in the superframe of given are provided.

  According to another embodiment, in the method, the transmit data interface forms part of an electronic device that communicates with the receive data interface of the electronic device via a communication path, the method further comprising: Including sending a data stream to the data interface.

  According to another embodiment, the receive data interface includes a receive data allocation circuit, the method receives a transmit data stream at the receive data interface, and a plurality of traffic at the receive data allocation circuit of the receive data interface. Further comprising reconfiguring the channel.

  According to another embodiment, in the method, the electronic device comprises a plurality of endpoints, and the method also includes providing a reconfigured traffic channel to each endpoint of the plurality of endpoints.

  According to another embodiment, in the method, the electronic device comprises a plurality of speakers, and the method also includes providing a reconfigured traffic channel to each speaker of the plurality of speakers.

  According to another embodiment, in the method, the traffic channel carries audio data and combining the data from each of the plurality of traffic channels into a single data stream is from each of the plurality of traffic channels. Synthesizing audio data into a single data stream.

  According to another embodiment, in the method, at least some slots of each frame are empty and transmitting the data stream includes transmitting a frame that includes the empty slot.

  According to one embodiment, in an electronic device configured to receive data from an electronic device via a communication path, an audio connector in the path having at least first and second terminals and a difference from the first and second terminals. An electronic device comprising: a differential receiver that receives a dynamic data signal and provides a corresponding digital data stream; and a data interface that receives the digital data stream and extracts a plurality of data traffic channels from the digital data stream Is provided.

  According to another embodiment, the electronic device also includes a plurality of speakers, and the data interface provides each of the extracted traffic channels to each of the speakers.

  According to another embodiment, in the electronic device, the digital data stream includes a plurality of superframes, each superframe includes a plurality of frames, each frame includes a plurality of data slots, and the data interface includes: A data allocation circuit is provided for extracting a plurality of data traffic channels from the digital data stream.

  According to another embodiment, in the electronic device, the digital data stream includes a plurality of superframes, each superframe includes a plurality of frames, and each frame includes a plurality of data slots including at least one boundary slot. The boundary slot carries data for one traffic channel of the plurality of traffic channels in a first subset of frames within a given superframe, and the boundary slot further comprises a given superframe A data subset carrying data for another of the traffic channels in a second subset of frames in the data interface, the data interface comprising a data allocation circuit for extracting a plurality of data traffic channels from the digital data stream Eteiru.

  According to another embodiment, in the electronic device, the data interface comprises a plurality of buffers coupled to a data allocation circuit, and each of the plurality of data traffic channels passes through each of the buffers.

  According to another embodiment, the electronic device also includes at least one microphone that collects the microphone signal, and the data interface is configured to transmit the microphone signal in digital form over the communication path.

  According to another embodiment, in the electronic device, the audio connector includes a male tip-ring-ring-sleeve audio connector.

  According to one embodiment, an audio circuit that generates digital audio signals on a plurality of traffic channels, a connector having at least first and second contacts and electrically coupled to a wired communication path, and a superframe. A data interface circuit for transmitting a digital audio signal through first and second contacts in a data stream, wherein each superframe includes a plurality of frames, each frame having a plurality of data slots, at least some The data slot is provided with an electronic device filled with a digital audio signal.

  According to another embodiment, in the electronic device, the plurality of traffic channels includes at least first and second traffic channels having different capacities, and the data interface circuit is configured to operate in a data slot filled with a digital audio signal. It is configured to transmit data bytes for the first and second traffic channels.

  According to another embodiment, in the electronic device, at least some of the data slots in each frame are empty and the connector includes an audio connector.

  According to another embodiment, in the electronic device, the audio connector includes at least a tip contact, a ring contact, and a sleeve contact.

  According to another embodiment, in the electronic device, at least one of the data slots is a boundary slot that carries the first and second traffic channels in each frame.

  According to another embodiment, the electronic device also includes a differential transmitter associated with the data interface circuit that transmits the data stream through the first and second contacts, wherein the first and second contacts are part of the audio connector. And selected from the group consisting of a left audio contact, a right audio contact, a microphone contact, and a ground contact.

  The foregoing description is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. The above embodiments may be embodied individually or in any combination.

10: system 12: electronic device 14: external device 16: path 18: data interface circuit 20: data interface circuit 22: end point 34: audio plug 38: audio jack 48: tip region 50, 52: ring 54: sleeve region 56 : Insulating area 70: Cable 74: Tip contact 76 and 78: Ring area 80: Sleeve terminal 88: Conductive line 160 and 164: Switching circuit 170 and 174: Analog signal line 172 and 176: Digital signal line 180: Audio circuit 182 : Audio codec 184: Analog / digital converter 186: Digital / analog converter 188: Digital signal processor 190: Input / output line 200, 202: Endpoint 2 12: Path 214: Buffer 216: Data allocation circuit 218: Channel allocation setting 220: Buffer 222: Path

Claims (14)

In a method for carrying data over a communication path,
Obtaining data corresponding to multiple traffic channels at the transmit data interface;
Combining data from each of a plurality of traffic channels into a single data stream with a transmit data allocation circuit in the transmit data interface;
And the data stream includes a stream of superframes, each superframe includes a plurality of frames, each frame includes a plurality of data slots including at least one boundary slot, the boundary slot being a given Carry data for one of the plurality of traffic channels in a first subset of frames in a superframe, and the boundary slot includes a plurality of frames in a second subset of frames in a given superframe. A method that carries data for another of the traffic channels. The transmit data interface forms part of an electronic device that communicates with a receive data interface of an electronic device via a communication path, the method further comprising:
Transmitting a data stream at the transmit data interface to the receive data interface;
The method of claim 1 further comprising: The received data interface includes a received data allocation circuit, and the method comprises:
Receiving a transmit data stream at the receive data interface;
Reconfiguring a plurality of traffic channels in the received data allocation circuit of the received data interface;
The method of claim 2 further comprising: The electronic device comprises a plurality of endpoints, the method comprising:
Providing the reconfigured traffic channel to each endpoint of the plurality of endpoints;
The method of claim 3 further comprising: The electronic device includes a plurality of speakers, and the method includes:
Providing the reconfigured traffic channel to each of the plurality of speakers;
The method of claim 3 further comprising:   The traffic channel carries audio data and combines the data from each of the plurality of traffic channels into a single data stream, the step of combining the audio data from each of the plurality of traffic channels into a single data stream 4. The method of claim 3, comprising:   The method of claim 2, wherein at least some slots in each frame are empty, and the step of transmitting a data stream comprises transmitting a frame that includes empty slots. In an electronic device configured to receive data from an electronic device via a communication path, an audio connector in the path having at least first and second terminals;
A differential receiver for receiving a differential data signal from first and second terminals and providing a corresponding digital data stream;
A data interface for receiving the digital data stream and extracting a plurality of data traffic channels from the digital data stream;
Equipped with a,
The digital data stream includes a plurality of superframes, each superframe includes a plurality of frames, each frame includes a plurality of data slots including at least one boundary slot, the boundary slot being a given slot Carrying data for one of the traffic channels in the first subset of frames in the superframe, and the boundary slot of the traffic channel in the second subset of frames in a given superframe An electronic device that carries data for another traffic channel .   9. The electronic device of claim 8, further comprising a plurality of speakers, wherein the data interface provides each of the extracted traffic channels to each of the speakers. The data interface is
A data allocation circuit for extracting a plurality of data traffic channels from the digital data stream;
The electronic device according to claim 9, comprising: The electronic device of claim 10 , wherein the data interface comprises a plurality of buffers coupled to a data allocation circuit, and each of a plurality of data traffic channels passes through each of the buffers. 12. The electronic device of claim 11 , further comprising at least one microphone that collects a microphone signal, wherein the data interface is configured to transmit a digital form of the microphone signal over a communication path.   The electronic device of claim 9, wherein the audio connector comprises a male tip, ring, ring, sleeve audio connector. An audio circuit for generating digital audio signals in a plurality of traffic channels;
A connector having at least first and second contacts and electrically coupled to the wired communication path;
A data interface circuit for transmitting a digital audio signal through first and second contacts in a data stream having a superframe;
Each superframe includes a plurality of frames, each frame including a plurality of data slots including at least one boundary slot, wherein the boundary slots are in a first subset of the frames in a given superframe. A digital audio signal for one of the traffic channels is carried, and the boundary slot is a digital audio signal for another of the traffic channels in a second subset of frames within a given superframe. To transport electronic devices.

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